Plasmonic hot electron induced layer dependent anomalous Fröhlich interaction in InSe

Abstract Despite the great promise of InSe for electronic and optoelectronic applications, Fröhlich interaction plays an important role in electrical transport due to the polar nature of it, which can become more significant in reduced dimensionality. Here, we report on how the dimensionality influe...

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Bibliographic Details
Published inCommunications physics Vol. 4; no. 1; pp. 1 - 8
Main Authors Rahaman, Mahfujur, Aslam, Muhammad Awais, He, Lu, Madeira, Teresa I., Zahn, Dietrich R. T.
Format Journal Article
LanguageEnglish
Published London Nature Publishing Group 30.07.2021
Nature Portfolio
Subjects
Coupling
Current carriers
Energy gap
Hot electrons
Nanoelectronics
Nanotechnology devices
Optoelectronics
Phonons
Physics
Plasmonics
Raman spectroscopy
Room temperature
Semiconductors
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Summary:Abstract Despite the great promise of InSe for electronic and optoelectronic applications, Fröhlich interaction plays an important role in electrical transport due to the polar nature of it, which can become more significant in reduced dimensionality. Here, we report on how the dimensionality influences the strength and nature of the Fröhlich polaronic effect in InSe with the aid of plasmonic hot electrons injection. Polar optical phonons couple to hot electrons via the Fröhlich interaction in InSe and enable us to monitor them in conventional Raman measurements. We observed that the intensity of these phonon modes initially increases gradually with decreasing layer number and then drops drastically from 7 L to 6 L (transition from quasi-direct to indirect bandgap at room temperature). Additionally, a gradual decrease of intensity of the polar modes with further decreasing layer number is observed due to the increasing indirect bandgap nature of InSe suggesting reduced Fröhlich coupling below this thickness.
ISSN:2399-3650
2399-3650
DOI:10.1038/s42005-021-00674-5